Showing papers in "Clinical and Experimental Ophthalmology in 2007"

Stromal haze after combined riboflavin-UVA corneal collagen cross-linking in keratoconus: in vivo confocal microscopic evaluation.

Abstract: The technique of corneal collagen cross-linking consists of photopolymerization of stromal fibres by the combined action of a photosensitizing substance (riboflavin or vitamin B2) and ultraviolet light from a solid state UVA source. Photopolymerization increases the rigidity of corneal collagen and its resistance to keratectasia. In this report we present two cases, studied through in vivo confocal microscopy, with stage III keratoconus that developed stromal haze after the cross-linking treatment.

Contemporary in vivo confocal microscopy of the living human cornea using white light and laser scanning techniques: a major review

Abstract: In vivo confocal imaging of the cornea has evolved exponentially over the last few decades and it has increasingly emerged from the laboratory to be used in the clinical setting in relation to inherited corneal diseases, corneal infections, contact lens wear and the effects of corneal surgery. This evolution has led to significant enhancement of our knowledge of the living cornea in both its physiological and pathological states. A number of in vivo confocal microscope devices using white, and more recently coherent, light sources have been developed to provide non-invasive assessment of the corneal microstructure at a lateral resolution of 1-2 microm. The fundamental principles of in vivo confocal microscopy and the key differences between these devices are highlighted in this review. By providing a systematic review of the extensive literature on the human cornea, this perspective paper aims to provide an overview of how in vivo confocal microscopy has contributed to our greater understanding of the human cornea in health, in disease, and following surgery, with a particular emphasis on quantitative data. The utility and limitations of available data are highlighted as are possibilities for the future development of this innovative technology.

Genetic testing for retinal dystrophies and dysfunctions: benefits, dilemmas and solutions.

Abstract: Human retinal dystrophies have unparalleled genetic and clinical diversity and are currently linked to more than 185 genetic loci. Genotyping is a crucial exercise, as human gene-specific clinical trials to study photoreceptor rescue are on their way. Testing confirms the diagnosis at the molecular level and allows for a more precise prognosis of the possible future clinical evolution. As treatments are gene-specific and the 'window of opportunity' is time-sensitive; accurate, rapid and cost-effective genetic testing will play an ever-increasing crucial role. The gold standard is sequencing but is fraught with excessive costs, time, manpower issues and finding non-pathogenic variants. Therefore, no centre offers testing of all currently 132 known genes. Several new micro-array technologies have emerged recently, that offer rapid, cost-effective and accurate genotyping. The new disease chips from Asper Ophthalmics (for Stargardt dystrophy, Leber congenital amaurosis [LCA], Usher syndromes and retinitis pigmentosa) offer an excellent first pass opportunity. All known mutations are placed on the chip and in 4 h a patient's DNA is screened. Identification rates (identifying at least one disease-associated mutation) are currently approximately 70% (Stargardt), approximately 60-70% (LCA) and approximately 45% (Usher syndrome subtype 1). This may be combined with genotype-phenotype correlations that suggest the causal gene from the clinical appearance (e.g. preserved para-arteriolar retinal pigment epithelium suggests the involvement of the CRB1 gene in LCA). As approximately 50% of the retinal dystrophy genes still await discovery, these technologies will improve dramatically as additional novel mutations are added. Genetic testing will then become standard practice to complement the ophthalmic evaluation.

Retinal vessel diameter in normal and glaucomatous eyes: the Beijing eye study.

Abstract: Purpose: To assess retinal vessel diameter in adult Chinese with and without glaucoma. Methods: The population-based, cross-sectional study included 4439 of the 5324 subjects asked to participate (response rate 83.4%), all aged 40 years or older. This study was divided into a rural part (1973 subjects [44.4%]) and an urban part (2466 subjects [55.6%]). Colour optic disc and fundus photographs were morphometrically examined for 2418 subjects. The retinal vessel diameters were measured at the optic disc border and at a distance of 2 mm to the optic disc border. The main outcome measure was the retinal vessel diameter. Results: Diameters of the retinal arteries were significantly (P < 0.001) the widest in the temporal inferior region, followed by the temporal superior region (P < 0.001), the nasal superior region (P < 0.001) and finally the nasal inferior region. Except for the nasal inferior vein, the same held true for the retinal veins. The sequence of the main four vessel trunks with respect to their diameters was not associated with age, gender or hyperopia versus myopia. The artery diameters showed a tendency to decrease in older age, while the vein diameters decreased across all age groups. Eyes with glaucomatous optic nerve damage showed significantly (P < 0.001) thinner arteries while the retinal vein diameters were not different. Conclusions: Diameters of the retinal arterioles and veins are the widest in the temporal inferior arcade, followed by the temporal superior arcade, the nasal superior arcade and finally the nasal inferior arcade. Retinal artery diameters decrease with glaucoma, and retinal vein diameters decrease with age.

Fungal keratitis in Melbourne

Abstract: Background: Description of the clinical and microbiological spectrum of fungal keratitis at a tertiary eye care hospital in Melbourne, Australia. Methods: Retrospective review of all patients with keratitis with positive fungal cultures from corneal or associated samples presenting to the Royal Victorian Eye and Ear Hospital, Melbourne, Australia from July 1996 to May 2004. Demographic data, predisposing factors, features on presentation, management, outcomes and microbiological data were collected and analysed. Results: The study included 56 eyes of 56 patients. Thirtyfive patients were treated as ‘typical’ fungal keratitis and used for description and analysis, with a mean follow up of 18 months. Ocular trauma (37.1%), chronic steroid use (31.4%) and poor ocular surface (25.7%) were the major predisposing factors. Perforation was seen in 25.7% of patients, penetrating keratoplasty was required in 9 (25.7%) patients and evisceration was performed in 2 (5.7%) patients. Candida albicans (13 patients, 37.2%) was the most common fungal isolate accounting for more than one-third of all organisms followed by Aspergillus fumigatus (six patients, 17.1%) and Fusarium sp. (five patients, 14.3%). Conclusions: The present study describes the clinical patterns of fungal keratitis in Melbourne, Australia and contrasts them with reports from other areas of the world. A high incidence of C. albicans infection and the prior use of steroids in high proportion of the patients are highlighted in this study.

Ocular toxicity of fluoroquinolones.

Abstract: The ocular toxicity of fluoroquinolones and the risks of their use in the treatment of ocular infection were reviewed. Systematic identification, selection, review and synthesis of published English-language studies relating to fluoroquinolone use and safety in animals and humans was conducted. Although not free of complications, fluoroquinolones are generally safe when used to treat ocular infection. Ocular toxicity appears to be dose-dependent and results from class-effects and specific fluoroquinolone structures. Phototoxicity and neurotoxicity have been reported, and toxic effects on ocular collagen may be associated with Achilles tendinopathy. Corneal precipitation may provide an advantageous drug depot but delay healing and result in corneal perforation in approximately 10% of cases. Although human toxicity studies are limited, the current recommended dose for intracameral injection of ciprofloxacin is less than 25 microg. Intravitreal injections of ciprofloxacin 100 microg, ofloxacin 50 microg/mL, trovafloxacin 25 microg or less, moxifloxacin 160 microg/0.1 mL or less and pefloxacin 200 microg/0.1 mL are considered safe.

Subthreshold micropulse diode laser photocoagulation for clinically significant diabetic macular oedema: a three-year follow up.

Abstract: Purpose: To report the long-term visual outcome of subthreshold micropulse diode laser photocoagulation for clinically significant diffuse diabetic macular oedema (CSME). Design: Non-comparative case-series. Methods: The main outcome measures of this 3-year follow-up study of infrared (810 nm) subthreshold diode micropulse laser photocoagulation for CSME were visual outcome and the angiographic CSME status of 19 patients (25 eyes). Results: Visual acuity stabilized or improved in 84% of treated eyes by the end of the first year. The result was maintained in the second year and by the third year, 92% maintained vision. However, more patients needed supplementary grid laser in the third year than in the second year. CSME decreased in 92% of the eyes and resolved in 88% in the first year. By the second year, 92% showed complete resolution. However, in the third year, recurrent CSME was noted in 28% of patients. Conclusion: This study has the longest follow up reported so far and demonstrating that subthreshold micropulse diode laser photocoagulation has a beneficial long-term effect on visual acuity and resolution of CSME with minimal chorio-retinal damage.

Bevacizumab inhibits corneal neovascularization in an alkali burn induced model of corneal angiogenesis.

Abstract: Background: New and uncontrolled blood vessel development in the cornea is a pivotal process in the pathogenesis of several corneal diseases. These corneal diseases may finally cause blindness and managing them therapeutically is problematic. The data supporting a causal role for vascular endothelial growth factor in corneal neovascularization are extensive. This study aimed to evaluate the effect of subconjunctival bevacizumab (Avastin) on experimental corneal neovascularization in rabbits. Methods: Chemical cauterization of the cornea was performed by touching central cornea with a 5-mm-diameter NaOH-soaked cotton applicator for 10 s in 20 eyes of 20 White New Zealand rabbits. The rabbits were then divided randomly into two equal groups. Bevacizumab (2.5 mg) was administered to 10 eyes (group 1) by a subconjunctival injection immediately after chemical cauterization of corneal surface. As a control, 10 eyes (group 2) received an injection of distilled water. Rabbits were examined daily for detection of the first signs of neovascularization. Three weeks later, the extent of corneal neovascularization was evaluated by direct examination and photograph analyses. Total corneal neovascularization area, degree of circumference involved and longest neovascular pedicle length were assessed. Results: Bevacizumab significantly decreased the total neovascularization area (P < 0.009), the circumference involved (P < 0.011) and the longest neovascular pedicle length (P < 0.023). Conclusion: Local injection of bevacizumab has a significant effect on inhibition of alkali burn-induced corneal neovascularization. This shows the potential value of bevacizumab in the treatment of corneal neovascularization.

Management of metastatic carcinoma of the uveal tract: an evidence-based analysis.

Abstract: Uveal metastasis from carcinoma is the most common cause of ocular malignancy in adults and represents an increasing problem in the context of an ageing population and enhanced survival of stage IV cancer patients. The reported prevalence of clinically evident uveal metastases in carcinoma patients ranges from 2% to 9%, with breast and lung cancer together accounting for between 71% and 92% of cases. Most patients (66-97%) have a known history of cancer and, although the majority have metastatic lesions elsewhere, up to 33% may present with an isolated ocular metastasis. These lesions may progress rapidly and are potentially sight-threatening. Early diagnosis and appropriate timely treatment are therefore of paramount importance to maintain patients' quality of life. The diagnosis is usually clinical and detailed descriptions of symptomatology and physical characteristics are provided. In 21-50% of patients, involvement is bilateral. External beam radiotherapy (EBRT), chemotherapy, hormone and biological therapies, brachytherapy, transpupillary thermotherapy, laser photocoagulation/photodynamic therapy and enucleation are therapeutic modalities described in the literature for the management of uveal metastases. The strongest evidence favours timely EBRT for the management of sight-threatening uveal metastases. The published evidence supporting EBRT for sight-threatening uveal metastases was given a grade B (strong support for recommendation). Newer alternative therapies are emerging and may have a role in selected patients; however, there are unfortunately few large studies examining such treatments for carcinoma metastatic to the eye. The role of these modalities will be further clarified with the results of larger comparative trials.

Long-term functional outcome of macular hole surgery correlated to optical coherence tomography measurements.

Abstract: Objective Evaluation of long-term functional outcome after macular hole surgery and its correlation with postoperative optical coherence tomography (OCT). Methods Before and after surgery a complete clinical examination and OCT were performed in 38 patients. Best corrected postoperative visual acuity (VA) was correlated to the following OCT parameters: preoperative base and minimum diameter of the hole, hole height, hole form factor, retinal thickness and nerve-fibre layer measurements postoperatively, postoperative foveal contour, appearance of retinal pigment epithelium layer and photoreceptor layer. Results Over a mean follow up of 67 months, VA improved significantly (P=0.01). Retinal thickness and retinal thickness and nerve-fibre layer measurements of the operated eye did not differ from fellow eye. A negative correlation was seen between final VA and preoperative base diameter of the hole (r=-0.41, P=0.02) and hole height (r=-0.45, P=0.01). The correlation between hole form factor values and final VA (r=0.36, P=0.04) was weak. Appearance of the photoreceptor band was the only OCT parameter significantly correlating with final VA (r=-0.42, P=0.01) and explaining the observed increase (r=-0.32, P=0.05) in VA. Conclusion Appearance of the photoreceptor layer on postoperative OCT correlates to functional outcome and may help to explain cases of unsatisfactory postoperative VA despite successful hole closure.

Pterygium in Tibetans: a population‐based study in China

Abstract: Purpose: To describe the prevalence and to identify associated risk factors for pterygium in a Tibetan population at high altitude in Zeku County, China. Methods: A prospective population-based survey was conducted from October to December 2006. A stratified, clustered, randomized sampling procedure was used to select 2632 Tibetan people aged 40 years and older. Pterygium was diagnosed and graded clinically as grade 1 (transparent), 2 (intermediate) and 3 (opaque). Risks factors associated with pterygium were evaluated with logistic regression models. Results: From a total of 2632 eligible subjects, 2229 (84.69%) were examined. There were 323 people with pterygium, equivalent to an overall prevalence of 14.49% (95% confidence interval [CI] 13.03–15.95). Pterygium was independently associated with increasing age for persons aged 70–79 years, compared with those aged 40–49 years (odds ratio [OR] 2.0; 95% CI 1.4–2.8), female gender (OR 1.6; 95% CI 1.2–2.0), dry eye symptoms (OR 1.3; 95% CI 1.0–1.7), seldom use of sunglasses/crystal spectacles (OR 4.6; 95% CI 1.9–11.3) or hats (OR 3.6: 95% CI 2.4–5.4), lower education level (<3 years) (OR 1.6; 95% CI 1.1–2.4) and low socioeconomic status (OR 1.9; 95% CI 1.5–2.4). Conclusions: The prevalence of pterygium in a Tibetan population at high altitude is significantly high, particularly in certain at-risk groups. The primary causative factors are related to ocular sun exposure, which are easily preventable. Public health schemes to address this serious health issue are urgently needed.

Periocular squamous cell carcinoma

Abstract: Squamous cell carcinoma (SCC) is the second most common eyelid malignancy and its incidence is increasing. Because of its variable clinical presentation, SCC may be difficult for even the experienced clinician to diagnose. Hence, all suspicious lesions warrant biopsy. As SCC behaviour may range widely in aggression, management should be individualized based on tumour (e.g. size, location, grade, histological subtype, previous recurrence, perineural invasion) and patient factors (e.g. age, health). Treatment of eyelid SCC should include margin control whenever possible for the highest cure rate in this high-risk area. Immediate histological monitoring of surgical margins with frozen sections or Mohs' micrographic surgery also allows for smaller margins of excision in an area where tissue conservation is important. Other special considerations in the periocular area include maintaining a high level of suspicion for perineural invasion as this may be associated with a poorer prognosis.

Amniotic membrane transplantation for ocular surface reconstruction: indications and outcomes.

Abstract: Background: The amniotic membrane is a useful tool in the management of several ocular surface diseases. Despite numerous studies, standardization of the use of the membrane and of outcome measures is lacking. Herein, the authors’ results of amniotic membrane transplantation (AMT) in ocular surface reconstruction against defined outcome measures are reported. Methods: A retrospective case study of 74 consecutive procedures (58 patients) performed against predefined outcome measures. The cases were divided into three groups. Group A AMT in the presence of stem cell loss (32 procedures), Group B AMT without stem cell loss (24 procedures) and Group C AMT for conjunctival reconstruction (18 procedures). The outcomes were evaluated against defined criteria based on the purpose (patch or graft) and objective for use of the membrane. Results were analysed by defining the outcomes as success, partial success or failure. Results: Unequivocal success of the procedure was observed in 22% in Group A, 62.5% in Group B and 50% in Group C. AMT was significantly more successful in the presence of functioning stem cells (P = 0.01). In Group A acute and subacute cases (less than 3 months) needed more procedures compared with chronic cases (P = 0.02). In Group C, results were comparatively worse when AMT was used in progressive cicatrizing conditions. Conclusion: Use of AMT can be associated with a significant number of failures. It provides a useful alternative for specific indications where its use should be encouraged. It is important to define criteria for success in order to accurately evaluate efficacy.

Association between stature, ocular biometry and refraction in an adult population in rural Myanmar: the Meiktila eye study.

Abstract: Purpose: To study the association between adult stature and ocular biometric parameters and refraction. Methods: In a population-based cross-sectional ophthalmic survey of 2418 adults (≥40 years old) living in the rural villages in central Myanmar, height and weight were measured using a standardized protocol, and body mass index was calculated. Non-cycloplegic refraction and corneal curvature were determined by an autorefractor. Ultrasound pachymetry was performed and ocular biometry, including axial length, anterior chamber depth, lens thickness and vitreous chamber length were measured using A-mode ocular ultrasonography. Results: Height and weight were significantly correlated with age, gender and all the ocular biometric parameters, except lens thickness. After adjusting for age and gender, taller and heavier persons had eyes with longer axial length, deeper anterior and vitreous chambers, and flatter and thicker corneas than shorter persons. Height was not significantly correlated with refraction, and heavier persons tended to be less myopic (P < 0.001). Multivariate linear regression models revealed consistent results with the findings for association between height, weight and ocular biometry and refractive error. Conclusions: Adult stature is independently associated with vitreous chamber length and corneal radius in this Burmese population. Heavier persons were slightly hyperopic.

How significant is a family history of glaucoma? Experience from the Glaucoma Inheritance Study in Tasmania.

Abstract: To determine what proportion of primary open angle glaucoma (POAG) in Tasmania, Australia is familial.

Alterations of retinal pigment epithelium in central serous chorioretinopathy.

Abstract: Background: To examine with en face optical coherence tomography (OCT) the alterations of retinal pigment epithelium (RPE) in central serous chorioretinopathy (CSC) and their role in the pathophysiology of CSC. Methods: We examined retrospectively 30 consecutive eyes of 30 patients with various phases of CSC. All patients underwent fluorescein angiography, indocyanine green angiography, and en face and longitudinal OCT examinations. Results: Of 25 eyes with acute CSC, en face OCT showed RPE abnormalities in 22 eyes (88%) with pigment epithelial detachment (PED) in nine eyes (36%) and a small bulge of RPE in the posterior pole in 15 eyes (60%). Of four eyes with chronic CSC, OCT showed PED in one eye (25%) and a small bulge of RPE in other three eyes (75%). Of 29 eyes with acute or chronic CSC, fluorescein angiography showed characteristic pinpoint leakage in 20 eyes (69%). Of these 20 eyes, a leaking point was located within PEDs in five eyes (25%) and was consistent with the bulge of RPE in nine eyes (45%). With indocyanine green angiography, 28 (97%) eyes showed choroidal vascular hyperpermeability. Ten of the 11 eyes with PED (91%) showed PED within the areas of choroidal vascular hyperpermeability. Sixteen of the 18 eyes with a bulge of RPE (89%) showed the bulge within areas of choroidal vascular hyperpermeability. The one eye in the quiescent CSC exhibited multiple small PEDs within the areas of choroidal vascular hyperpermeability by en face OCT.

Aberration and contrast sensitivity comparison of aspherical and monofocal and multifocal intraocular lens eyes

Abstract: Background: Higher-order aberrations and contrast sensitivity were evaluated in patients who underwent phacoemulsification cataract extraction followed by implantation of aspherical, monofocal or multifocal intraocular lens (IOL) replacements. Methods: In this comparative trial, 124 patients with an average age of 66.8 ± 5.2 years and their 124 eyes were randomly divided into three surgical implantation groups to receive one of three types of IOLs in replacement of cataract lenses. The patients of group 1 were given an aspherical IOL Z9001 (AMO, Santa Ana, CA, USA) replacement, and group 2 was implanted a monofocal IOL SA60AT (Alcon, Fort Worth, TX, USA) and group 3 the multifocal IOL SA40N (AMO). Post-surgical best-corrected visual acuity, corneal aberrations, total ocular aberrations, pupil diameters, capsulorhexsis sizes and contrast sensitivity were measured and compared. Results: There was no statistical difference for mean best-corrected visual acuity, pupil diameter, curvilinear capsulorhexis size and corneal aberration among the three groups. For the spherical aberration, fourth-order higher-order aberration and total ocular higher-order aberration, the SA40N group was higher than the SA60AT group and the SA60AT group was higher than the Z9001 group, and the differences between the three groups were statistically significant for these measurements. Contrast sensitivity was higher for the Z9001 group than the SA60AT group and the SA60AT group was higher than the SA40N group, and the difference was statistically significant in all the spatial frequencies of 3, 6, 12 and 18. Conclusions: Although the multifocal IOL can provide near vision, it can increase higher-order aberration and negatively influence contrast sensitivity. However, the aspherical IOL can reduce aberration and improve contrast sensitivity as compared with the monofocal IOL.

Clinical outcomes of keratitis.

Abstract: Objection: To analyse the patient, clinical and microbiological variables associated with poor outcomes from keratitis in patients presenting to a major public hospital in Australia. Methods: A retrospective audit of the records of all patients who had a corneal scraping in 5 years at Princess Alexandra Hospital (Brisbane, Australia) was carried out. The outcome of a patient's episode of keratitis was classified as poor if they had final visual acuity of 6/60 or worse; had vision loss during treatment; or a complication of keratitis; or needed surgical intervention. Results: A final outcome was established in 207 cases during the 5-year period. Final vision of 6/12 or better was found in 48% (100) of cases while a poor outcome was seen in 28% (58). Linear regression showed poor outcomes were directly associated with age (P < 0.001) and disease severity (P < 0.001). Univariate analysis indicated that poor outcomes were more likely in patients who had had prior ocular surgery (P = 0.005) or ocular surface disease (P = 0.01) and were also associated with presenting visual acuity of worse than 6/60 (P < 0.001) and isolation of Streptococcus pneumoniae (P = 0.002). While patients with traumatic keratitis, contact lens-related keratitis or negative corneal cultures (P = 0.009) were more likely to have good outcomes. Multivariate analysis showed that the relative risk of a patient having a poor outcome was 4.3× (CI 2.0–9.5) if they had severe keratitis, 4.1× (CI 1.8–9.5) if they had keratitis related to ocular surface disease and 3.8× (CI 1.8–8.3) if they were over 50 years old. Conclusions: An outcome of poor vision, vision loss during treatment, surgical intervention or complication of keratitis is more likely in patients with severe keratitis, keratitis related to prior ocular surface disease or older age.

Bevacizumab (Avastin) for the treatment of neovascular glaucoma.

Abstract: Herein three cases of angle closure secondary to neovascularization (elevated intraocular pressure in two of the cases) treated with the anti-vascular endothelial growth factor (VEGF) monoclonal antibody bevacizumab (Avastin) are reported. In all three cases there was rapid resolution of neovascularization and control of intraocular pressure. One patient with corneal anaesthesia from diabetes developed infectious keratitis, potentially as a consequence of inhibition of VEGF wound healing and neurotrophic functions. Avastin appears to have a promising role in the treatment of neovascular glaucoma but is not without potential local and systemic side-effects.

Comparison of acute structural and histopathological changes of the porcine ciliary processes after endoscopic cyclophotocoagulation and transscleral cyclophotocoagulation

Abstract: Background: The objective of this study is to investigate the acute histological effects of transscleral cyclophotocoagulation and endoscopic cyclophotocoagulation on the ciliary body and other structures of porcine eyes compared with untreated controls. Methods: Transscleral cyclophotocoagulation and endoscopic cyclophotocoagulation were performed on porcine eyes. Detailed histological evaluations were performed with light and scanning electron microscopy of treated eyes and compared with untreated controls. Results: Histological changes were observed with both light and scanning electron microscopy for all treated tissues. Tissue treated with transscleral cyclophotocoagulation showed pronounced tissue disruption of the ciliary body muscle and stroma, ciliary processes, and both pigmented and non-pigmented ciliary epithelium. Endoscopic cyclophotocoagulation-treated tissue exhibited pronounced contraction of the cilliary processes with disruption of the ciliary body epithelium, with less architectural disorginization and sparing of the ciliary body muscle. The sclera was not affected by either laser treatment. Conclusion: The endoscopic cyclophotocoagulation treatment caused less damage to the ciliary body compared with the transscleral cyclophotocoagulation when evaluated by light and scanning electron microscopy. Compared with transscleral cyclophotocoagulation, endoscopic cyclophotocoagulation appears to be a more selective form of cyclophotocoagulation resulting in less tissue disruption while achieving the goal of destroying ciliary body epithelium.

Demographic pattern, predisposing factors and management of ulcerative keratitis: evaluation of one thousand unilateral cases at a tertiary care centre.

Abstract: Purpose: To determine the predisposing factors, special clinical manifestations and the management of presumed microbial ulcerative keratitis. Methods: A retrospective study was performed in 1000 eyes of 1000 patients with presumed microbial keratitis. Information was recorded on patients’ age and gender, risk factors, seasonal presentation, number of days since initiation of ulcer, prior therapy, clinical presentation, microbiological work-up and case management. Results: Fifty per cent of the patients with corneal ulcers were aged between 36 and 65 years and 13.3% were in the paediatric age group (1 month to <16 years). The male : female ratio was almost 1.6:1. Only 11.4% of patients reported to the authors during the first week of initiation of ulcer. Trauma was the cause in 47.6% of eyes, and ocular surface diseases accounted for 16.6%. Forty-two per cent of eyes received topical antibiotics alone (either one or more) prior to hospital visit and 42.2% of eyes were on topical antibiotics and antifungals. Another 8.2% were on topical corticosteroids along with antibiotics and 4.6% were receiving some unidentified drop. Only 3% of the eyes did not receive any therapy prior to visit. Contact lens use as a risk factor could be identified only in 8.2% of eyes. Ulcers were central in location in 48%. Ulcer size 6–9 mm was observed in 51.7% of eyes. Medical therapy alone was effective in 61.0% of eyes and another 9.7% eyes responded to paramedian tarsorrhaphy along with topical antimicroboial drugs. Conclusion: Corneal ulcers are a frequent problem in this part of the world. The ulcers seen at this tertiary referral hospital present late in the natural history of the disease and are clinically severe. Despite the severity a majority of the eyes could be saved anatomically, but almost 65% of eyes were left with a visual acuity of <6/120. Considering the high magnitude of visual loss, public education about the potential for loss of sight and the importance of timely and appropriate treatment is recommended.

A prospective randomized treatment study comparing three treatment options for chalazia: triamcinolone acetonide injections, incision and curettage and treatment with hot compresses.

Abstract: Background: Three methods of treating chalazia were compared: intralesional triamcinolone acetonide injections (0.2 mL of 10 mg/mL), incision and curettage and advice regarding the application of hot compresses to the affected eyelid. Methods: This was a single centre randomized treatment study. Patients with a chalazion underwent either of the three treatment options. Chalazion resolution, pain, satisfaction and inconvenience experienced because of treatments were the outcomes assessed via a telephone interview at 3 weeks. Results: 136 consecutive patients were enrolled into the study. At the 3-week follow up, the resolution rates in the triamcinolone acetonide injection and surgical treatment groups were not significantly different from each other at 84% (47/56) and 87% (39/45), respectively (P < 0.001), but was significantly lower in the conservative treatment group at 46% (16/35) (P < 0.001). Pain scores were higher in the surgical treatment group compared with the triamcinolone injection group (P < 0.003). Inconvenience experienced by patients was reported as significantly less in the triamcinolone group compared with the conservative and surgical treatment groups (P < 0.001). Patient satisfaction scores were lower in the conservative treatment group compared with each of the other two groups which in turn, were no different from each other regarding this outcome (P < 0.001). Conclusions: To our knowledge, this is the first prospective randomized study comparing the three methods of chalazia treatment. Results suggest that a single triamcinolone acetonide injection followed by lid massage is almost as effective as incision and curettage in the treatment of chalazia and with similar patient satisfaction and less pain and patient inconvenience.

Medical treatment of cataract.

Abstract: The incidence of cataract continues to increase with the ageing of the population. Surgical treatment with phacoemulsification and intraocular lens implantation remains the only proven treatment. This, however, is associated with significant cost and is not readily available especially in the developing countries where the prevalence of cataract is the highest. Medical treatment of cataract is therefore a highly desired alternative. Since the last major review of medical treatment of cataract the search for an anti-cataract agent has advanced on many fronts. Some anti-cataract drugs, such as carnosine, have now reached clinical trials and showed encouraging results that warrant further investigation. The discovery of an effective medical treatment for cataract is likely to make global impact on eye health. The aims of this paper are to review the literature on the drug therapy of cataract and provide updates of the latest development.

Seropositivity rates for Bartonella henselae, Toxocara canis and Toxoplasma gondii in New Zealand blood donors

Abstract: Background: Bartonella henselae, Toxocara canis and Toxoplasma gondii organisms can all cause vision-threatening posterior segment disease. Diagnosis relies heavily on clinical findings, but detection of antibodies in the patient’s serum may be helpful in some cases. The significance of a positive serology result depends on the seroprevalence in the general population. Seroprevalence rates for these organisms vary widely around the world and this study aimed to determine the rates for a New Zealand population. Methods: One hundred and forty healthy blood donors from the Waikato region in the North Island of New Zealand had their serum tested using an indirect latex agglutination test for detection of T. gondii antibodies, an indirect immunofluorescent assay for B. henselae antibodies and an enzyme-linked immunosorbent assay test for T. canis antibodies. Results: Seropositivity rates for T. canis, T. gondii and B. henselae in this New Zealand population were 0.7 ± 1.65%, 42.9 ± 8.12% and 5 ± 3.61%, respectively. Conclusion: Seropositivity rates for T. gondii and B. henselae in New Zealand are similar to rates reported in some other countries; however, T. canis seroprevalence may be lower than reported elsewhere in the world.

Progression of retinopathy during pregnancy in type 1 diabetes mellitus

Abstract: Purpose: The incidence and risk factors for progression of retinopathy during pregnancy in women with type 1 diabetes mellitus were retrospectively evaluated. Methods: Fifty-four insulin-dependent diabetic patients at a teaching hospital in Saudi Arabia were followed throughout the pregnancy/puerperium with serial ophthalmic examination. Dilated fundus examination was performed in each trimester and puerperium. Results: Progression of diabetic retinopathy in the study occurred in 13/54 (24%) patients – 2/22 (9.1%) patients had no diabetic retinopathy initially, 4/20 (20%) had non-proliferative diabetic retinopathy (NPDR) and 7/12 (58.3%) had proliferative diabetic retinopathy (PDR). Of the eight patients with PDR who had no laser treatment before pregnancy, six (75%) showed progression but only one of the four patients who had PDR and laser treatment prior to pregnancy experienced progression of retinopathy. Eight patients in total received panretinal photocoagulation to arrest the progression of retinal disease during pregnancy and only one of them had laser treatment prior to pregnancy. Conclusion: Laser photocoagulation for severe NPDR or early PDR prior to pregnancy may protect against rapid progression of PDR. Visual impairment resulting from progression of PDR can be prevented by aggressive laser treatment during pregnancy. Duration of diabetes >15 years, poor glycaemic control and hypertension are high-risk factors in the progression of diabetic retinopathy in pregnancy.

Microbial keratitis following corneal transplantation

Abstract: Purpose: To determine the predisposing risk factors and analyse the clinical and microbiological profiles of microbial keratitis following corneal transplantation. Methods: A retrospective analysis was done of hospital records of all patients who presented with microbial keratitis in the corneal graft between July 2000 and June 2005 at the Corneal Unit of Royal Victorian Eye and Ear Hospital, Melbourne, Australia. Results: Eighty-one episodes of infection were identified in 62 patients over a 5-year period. Thirteen patients had multiple episodes of infection. The mean age of the patients was 70 ± 16 years (range: 22–92 years). The median time interval between the graft and infection was 17 months (range: 6 days to 385 months). Twenty-two (35%) episodes of primary infection were related to sutures. The associated predisposing risk factors were failed graft (40%), dry eye (18%), Herpes simplex keratitis (8%), and ocular surface disease (8%). Forty-seven (76%) cases were culture positive for bacteria. Ten cases were positive for Herpes simplex virus (HSV) during presentation. Conclusion: Failed graft is a long-term risk factor for graft infection in addition to ocular surface disease and H. simplex keratitis. All the predisposing risk factors increase the risk of recurrent graft infection.

Effect of statin drugs and aspirin on progression in open‐angle glaucoma suspects using confocal scanning laser ophthalmoscopy

Abstract: Purpose: To determine the effect of statins and aspirin on the rate of progression of optic nerve parameters in open-angle glaucoma (OAG) suspects, as defined by confocal scanning laser ophthalmoscopy (CSLO). Methods: Data of OAG suspects who had undergone at least two CSLO tests at the Beckman Vision Center at UCSF from January 2001 to June 2006 was collected. We conducted a retrospective chart review of 149 eyes from 76 patients considered suspect for glaucoma based on a cup-to-disc ratio >0.5, but with normal intraocular pressures (IOP) and visual fields. Subjects included glaucoma suspects who took statin drugs or aspirin for greater than 23 months. The control group consisted of suspects who never used statins or aspirin. The data were analysed using mixed effects regression. Results: When comparing controls with the statin group there were significant differences in the progression of multiple CSLO parameters per year, including rim volume (−13.7% controls, +26.7% statin only; P = 0.0156), retinal nerve fibre layer cross-sectional area (−12.2% controls, +24.3% statin only; P = 0.0051), and mean global retinal nerve fibre layer thickness (−10.3% controls, +26.6% statin only; P = 0.0114), with adjustment for age, gender, race, IOP, central corneal thickness, refractive error and multiple systemic comorbidities. No significant differences were found when comparing subjects taking a statin plus aspirin or aspirin alone with the controls. Conclusions: Statin drugs may be associated with slowed progression of optic nerve parameters in glaucoma suspects as measured by CSLO.

Outcomes in retinoblastoma, 1974-2005: the Children's Hospital, Westmead.

Abstract: Background: To report the 31-year experience of outcomes in retinoblastoma from a single centre. Methods: A retrospective analysis of consecutive cases of retinoblastoma diagnosed and treated at the Westmead Children’s Hospital, Sydney between 1974 and 2005 was performed. The subjects were analysed as two groups: those diagnosed between 1974 and 1989 (series α) and those diagnosed between 1990 and 2005 (series β). Results: There were a total of 142 patients included in the study, with a median follow up of 72 months. There were 84 patients with unilateral disease and 58 patients (116 eyes) with bilateral disease. The total enucleation rate remained high throughout both series for those with unilateral disease: 89% (series α) and 95% (series β). There was a reduction in enucleations performed for those with bilateral disease from 68.4% (series α) to 43.6% (series β) (P < 0.025). There were no bilateral enucleations performed after 1995. Actuarial Kaplan–Meier curves showed that 56% of all preserved eyes had not recurred at a median follow up of 95 months and 78.1% had avoided enucleation. Overall 43% of preserved eyes attained a visual acuity better than or equal to 6/12 and 55% achieved a visual acuity better than 6/60. There were four deaths due to retinoblastoma. Five patients were diagnosed with a second non-ocular malignancy. The most common treatment-related complications were cataracts, facial deformity, sepsis and febrile neutropaenia. Conclusions: The introduction of newer globe-preserving treatments for retinoblastoma was associated with equivalent visual outcomes, stable mortality rate and a greater number of short-term complications but avoided the late side-effects associated with external beam radiotherapy.

Surface modification of silicone intraocular lens by 2‐methacryloyloxyethyl phosphoryl‐choline binding to reduce Staphylococcus epidermidis adherence

Abstract: Purpose: To analyse the in vitro adherence of Staphylococcus epidermidis to the 2-methacryloyl oxyethyl phosphorylcholine (MPC)-modified silicone intraocular lens (IOL). Methods: The test IOLs were modified by using an air plasma treatment to bind MPC to the surface. The control IOLs were not modified. Chemical changes on the IOL surface were analysed by X-ray photoelectron spectroscopy (XPS) to confirm the covalent binding of MPC. IOL hydrophilicity was determined by measuring the water contact angle. Two different techniques, direct counting of viable adherent bacteria released by sonication, and scanning electron microscopy (SEM), were used to observe and compare the adherence of S. epidermidis to the IOLs after 1- and 18-h incubation. Results: XPS analysis confirmed that the test IOLs were surface-modified with MPC. The hydrophilicity of the IOLs was improved by surface modification, and the MPC-modified IOLs exhibited significantly reduced adhesion of S. epidermidis (P = 0.002) after an incubation period of 1 h. The SEM results showed that the MPC modification also suppressed the accumulation of bacteria and biofilm production after 18 h incubation. Conclusions: MPC-modified hydrophilic silicone IOLs reduce bacterial adherence and colonization, and thus may help reduce the incidence of postoperative endophthalmitis.

Early electroretinographic features of streptozotocin-induced diabetic retinopathy.

Abstract: Background: This study set out to document the early electrophysiological and immunohistochemical changes that occur in the retina of experimentally induced diabetic rats Methods: Diabetes was induced in rats by intraperitoneal injection of 60 mg/kg of streptozotocin (STZ) Electroretinogram readings were taken monthly under either short-duration or long-duration stimuli for up to 3 months after STZ Oscillatory potentials (OP) and the amplitudes and implicit times of a- and b-waves were analysed, and b-wave amplitudes were analysed using a Naka–Rushton fit Scotopic a-waves were analysed with photoreceptor models, and Rmp3 (the maximum a-wave amplitude) and S (sensitivity) were calculated Three months after STZ injection, immunohistochemistry for glial fibrillary acidic protein was performed on the retinas of the STZ-treated rats and age-matched controls Results: The implicit OP times were significantly longer in the diabetic rats as compared with the controls, and this difference was noted as early as 1 month following STZ treatment Other electrophysiological parameters, such as OP amplitudes, a- and b-wave amplitude as well as the implicit times, did not differ from controls at this stage The sacrificed STZ-treated rats also demonstrated marked enhancement of glial fibrillary acidic protein immunoreactivity, suggesting that at least in experimentally induced diabetic retinopathy there is increased Muller cell reactivity Conclusion: The results of this study indicated that functional alterations in the retina develop rapidly after the onset of diabetes Analysis of each electroretinogram component may be useful in further investigating the development mechanisms of diabetic retinopathy